Overview of the ARIES “Pathways” Program Farrokh Najmabadi UC San Diego US-Japan Workshop on Power Plants Study and Related Advanced Technologies with EU Participation UC San Diego, La Jolla, CA, USA 5-7 March 2008

US DOE has made no Commitment to Fusion Demo US Fusion program is viewed as a Science Program and not an energy program. FESAC activities FESAC Fusion Development Path Panel (2003) FESAC Strategic Planning Panel (2007) Community activities Proposal for many devices. ARIES pathways program A 3-year activity started in 2007.

A 35,000 ft view of fusion development landscape

Early US Fusion Development Path Partially integrated test of fusion plasmas and fusion technologies (Testing in “prototypical” environment) Full Integration of fusion plasma with fusion technologies (Test in “actual” environment) A “1st of the kind” Power Plant! “Fusion Power: Research and Development Requirements.” Division of Controlled Thermonuclear Research (AEC).

US Fusion Development Path (FESAC Report, 2003) 05 07 09 11 13 15 17 19 21 23 25 27 29 31 33 35 Configuration Optimization Concept Exploration/Proof of Principle 37 39 41 43 45 47 Theory, Simulation and Basic Plasma Science MFE PE(s) MFE ITER (or FIRE) Burning Plasma Materials Testing Materials Science/Development MFE IFMIF Engineering Science/ Technology Development Component Testing MFE CTF US Demo Demonstration Complete ITER Ops Phase 1 Complete IFMIF Ops 80 dpa Prelim. IFMIF Ops 150 dpa Internal Components Design Design Studies MFE Program

Demo Mission From FESAC Development Path Panel US Demo Mission: “Successful operation of the Demo convinces the users (Public, Regulators, Industry, power producers) that a commercial power plant can successfully meet all its objectives.” The ``first-generation'' plant MUST be attractive in terms of economics, safety, regulation, and environmental characteristics. Demo is used to label different devices with different mission among parties. The “perceived” required characteristics of an attractive power plant are different among parties. What is needed to convince the funding agencies that fusion is a viable power source are different among parties.

In the ITER area, we need to develop a 5,000 ft view of Fusion Development Landscape

The ARIES Pathways program is developing quantitative measures to assess fusion development needs and pathways What are the data bases needed to field a fusion power plant? Formed an Industrial Advisory Committee to help define R&D issues which are not usually considered by the scientific community (e.g., data base needed for licensing, operation, reliability, etc.) Developed “Technical Readiness Levels” as a quantitative measure of maturity and R&D needs in each technical area. TRL was originally introduced by NASA and is now adopted by DoD and recommended by GAO for “Technology” Development. TRL structure, however, is readily applicable to scientific areas. TRL structure provides a framework to plan and execute R&D programs as they can be utilized to assess cost, risk, and benefits of new initiatives. Used a system-based (concurrent physics/engineering) approach to identify interconnected physics/engineering constraints and issues

The first meeting of the ARIES Industrial advisory Committee meeting was held in June 2007. ARIES Program had a “utility advisory committee” in 90s. Their input was used subsequently in all ARIES Designs. They helped define mission of a Demonstration Power Plant (used in FESAC Development Path Panel report) Our new Industrial Advisory Committee includes members from US utilities, Vendors, Architect/Engineers, and regulatory agencies. Discussions in the first meeting of our new Industrial Advisory Committee revolved around Criteria for attractive fusion power.

Are the Prior EPRI Criteria for Practical Fusion Power Systems still valid? EPRI Criteria for Practical Fusion Power include: economics, public acceptance, and regulatory simplicity. Economics: Utilities will only be motivated to build a fusion power plant if it offers better economics than other options. The impact of environmental concerns on future energy prices, however, is not known. High reliability and availability are critical: Suggested targets are 70% for Demo and 90% for commercial plant. Steady state operation is essential. The Balance of Plant of a pulsed power source would be very expensive. There is a large effort in developing high-efficiency power conversion system for fossil fuels. Fusion should try to capitalize on these efforts. Public Acceptance: There is a large public sensitivity toward tritium.

The ARIES Pathways program is developing quantitative measures to assess fusion development needs and pathways What are the data bases needed to field a fusion power plant? Formed an Industrial Advisory Committee to help define R&D issues which are not usually considered by the scientific community (e.g., data base needed for licensing, operation, reliability, etc.) Developed “Technical Readiness Levels” as a quantitative measure of maturity and R&D needs in each technical area. TRL was originally introduced by NASA and is now adopted by DoD and recommended by GAO for “Technology” Development. TRL structure, however, is readily applicable to scientific areas. TRL structure provides a framework to plan and execute R&D programs as they can be utilized to assess cost, risk, and benefits of new initiatives. Used a system-based (concurrent physics/engineering) approach to identify interconnected physics/engineering constraints and issues.

Technical Readiness Levels provides a basis for development path analysis TRLs are a set of 9 levels for assessing the maturity of a technology (level1: “Basis principles observed” to level 9: “Total system used successfully in project operations”). Developed by NASA and are adopted by US DOD and DOE. Provide a framework for assessing a development strategy. Initial application of TRLs to fusion system clearly underlines the relative immaturity of fusion technologies compare to plasma physics. TRLs are very helpful in defining R&D steps and facilities.

Example: Fuel performance development in GNEP project

Example: TRLs for Plasma Facing Components. Power-plant relevant High-temperature gas–cooled PFCs Low-temperature water–cooled PFCs

The ARIES Pathways program is developing quantitative measures to assess fusion development needs and pathways What are the data bases needed to field a fusion power plant? Formed an Industrial Advisory Committee to help define R&D issues which are not usually considered by the scientific community (e.g., data base needed for licensing, operation, reliability, etc.) Developed “Technical Readiness Levels” as a quantitative measure of maturity and R&D needs in each technical area. TRL was originally introduced by NASA and is now adopted by DoD and recommended by GAO for “Technology” Development. TRL structure, however, is readily applicable to scientific areas. TRL structure provides a framework to plan and execute R&D programs as they can be utilized to assess cost, risk, and benefits of new initiatives. Used a system-based (concurrent physics/engineering) approach to identify interconnected physics/engineering constraints and issues

Our system-based approach has Highlighted several operation issues Acceptable variations in plasma power (n, T, …) during normal operation and impact on power handling equipment (Blankets are currently designed for steady loads.) Impact of power plant start-up scenarios (regulations dictate certification tests at different power levels) on plasma scenarios and power handling equipment. Precise, in-situ control of tritium breeding (too much breeding leads to very large inventories). Characterization of the Impact of off-normal events on power plant operation. Industrial approach to testing to develop highly reliable components.

Excess T production is a concern Blanket T production should be controlled in situ within 1%-2%.

The ARIES Pathways program is developing quantitative measures to assess fusion development needs and pathways What it the impact of each R&D item on the attractiveness of the final product? (Metrics for prioritization of R&D) Experience indicates that “optimum” design points are usually driven by the constraints. In some cases, a large design window is available when the constraint is “slightly” relaxed, allowing a more “robust” and credible design. Developed a new approach to Systems Analysis based on surveying the design space (instead of finding only an optimum design point) The data base currently contains over 106 self-consistent physics/engineering points. Modern visualization and data mining techniques are used to explore design space. This approach provides a direct measure of R&D on the characteristics of the final product. What are the possible embodiments for CTF and what are the their cost/performance attributes? (FY09 research)

Example of Design space for fusion power plants Contours of bn Contours of COE Contours of n/nGW

The ARIES Pathways program is developing quantitative measures to assess fusion development needs and pathways What it the impact of each R&D item on the attractiveness of the final product? (Metrics for prioritization of R&D) Experience indicates that “optimum” design points are usually driven by the constraints. In some cases, a large design window is available when the constraint is “slightly” relaxed, allowing a more “robust” and credible design. Developed a new approach to Systems Analysis based on surveying the design space (instead of finding only an optimum design point) The data base currently contains over 106 self-consistent physics/engineering points. Modern visualization and data mining techniques are used to explore design space. This approach provides a direct measure of R&D on the characteristics of the final product. What are the possible embodiments for CTF and what are the their cost/performance attributes? (FY09 research)

Thank you! Any Questions?